1. Field of the Invention
The present invention relates to a recording apparatus for recording an image on a recording medium. More particularly, the present invention is concerned with an image recording apparatus having a limited power source such as batteries.
The recording apparatus of the present invention is suitable for use in various apparatus such as electronic typewriters, desk-top calculators, word processors, copiers, printers, facsimiles and so on. The image which is handled by the recording apparatus of the present invention may be letters, numerals and/or patterns.
2. Related Background Art
Remarkable progress in the field of electronic engineering has made a great contribution to the reduction in the sizes of various electronic devices, which in turn has given a rise to the demand for devices having a high degree of portability. This applies also to the case of recording apparatus. Such portable recording apparatus essentially require a battery powered source. A typical example of a recording apparatus operable with battery power is a thermal printer which prints characters or patterns by locally heating a recording medium having a multiplicity of thermally developable dots of resistor. This type of printer is advantageous in that it enables the recording density to be freely controlled by varying the electric power supplied to the resistor. The control of the electric power source is usually conducted by means of so-called density adjusting dial which enables the electric power supplied to the resistor to be varied thereby effecting the control of the recording density. A high recording density requires correspondingly large electric power to be supplied to the resistor, with the result that the apparatus consumes a large amount of electric power and shortens the life of the battery.